Method for producing a bearing, and bearing

ABSTRACT

A method for producing a bearing, in particular a hydraulic axle support bearing, which comprises the following steps: preassembling an inner part in an outer part with an elastomer body which is arranged in between and is reinforced by a plastic cage which at least partially bears against an inner wall of the outer part. The plastic cage is configured to radially protrude over an upper edge and a lower edge of the out part and, at the lower edge of the outer part, to project over the latter. Simultaneously calibrating the outer part and the plastic cage by constricting the outer part and the plastic cage from a respective first diameter to a respective second diameter which is smaller than the respective first diameter. After the constriction, the plastic cage projects over the upper edge of the outer part for the form-fitting axial securing of the outer part.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 14/778,895, filed on Sep. 21, 2015 which is a U.S.national phase of application No. PCT/EP2014/053208, filed Feb. 19,2014, which claims priority from German application No. DE10 2013 204995.1, filed Mar. 21, 2013, each of which is herein incorporated byreference in its entirety.

FIELD OF THE INVENTION

The invention relates to a method for producing a bearing, in particulara hydraulic axle support bearing.

BACKGROUND OF THE INVENTION

The axle support bearings known in the prior art generally have an innerpart made of aluminium, a radial channel, an outer part and anelastomeric region which is arranged between the inner part and theouter part. The elastomeric region is reinforced by a steel cage or aplastic cage which has the advantage of reducing the weight of thebearing substantially. A steel cage is embedded into the rubber of theelastomeric region, for example, and then completely surrounded by therubber. In contrast, in the configurations known from the prior art, inwhich a weight-reducing plastic cage is used, only some areas of saidcage are surrounded by the elastomeric region. A bearing configured asan elastomeric bush bearing is known from DE 10 2007 022 410 A1.

Axle support bearings configured as described above need to becalibrated however. This is relatively uncomplicated if steel cages areused and the bearing is calibrated prior to assembly. Furthercalibration is then performed after assembly which ensures bothtightness and dimensional stability. During the latter calibration,several markings are pressed inwards at the periphery wherein thematerial of the outer part is pressed over the edge of the cage. Thisserves to connect the outer part to the inner part in the direction ofextrusion in a form fit manner over the elastomeric region. However, asalready stated, bearings with steel cages are very heavy.

If, on the other hand, the cage is made of plastic, calibration to applyincreased compressive prestressing in the elastomeric region isdifficult. However, this is necessary in terms of useful life,characteristic curve ratio and tight fitting of the plastic cage in thearrangement.

SUMMARY OF THE INVENTION

An object of the present invention is therefore to provide a method forproducing a weight-reducing bearing with plastic cage, by means of whichcalibration can be performed in a simple and cost-effective manner. Abearing with reduced weight produced accordingly should also beprovided.

This object is achieved through a method for producing a bearing havingthe features described herein.

A method for producing a bearing, in particular a hydraulic axle supportbearing, is provided, wherein the method comprises the following steps:preassembling an inner part in an outer part with an elastomer bodywhich is arranged in between and is reinforced by a plastic cage, whichat least partially bears against an inner wall of the outer part,wherein the plastic cage is designed to protrude radially over an upperedge and a lower edge of the outer part and, at the lower edge of theouter part, to project beyond the latter; and simultaneously calibratingthe outer part and the plastic cage by constricting the outer part andthe plastic cage from a respective first diameter to a respective seconddiameter which is smaller than the respective first diameter, wherein,after the constriction, the plastic cage likewise projects over theupper edge of the outer part for the form-fitting axial securing of theouter part.

The method enables easy and thus cost-effective calibration of both theouter part and, at the same time, the plastic cage in a single methodstep. The outer part is connected to the plastic cage in a form fitmanner in the end position which effects the required axial securing ofthe outer part. By way of an example, this also renders the markings andindentations on the outer part used in the prior art unnecessary.

Preferably, there is clearance, in particular of 2 mm, during thepre-assembly step. Moreover, it is preferred if the measurement of theconstriction of the outer part from the first diameter to the seconddiameter is greater than the above mentioned clearance, moreparticularly that the constriction measures more than 3 mm, preferablyapprox. 4 mm.

Preferably, the outer part is simply slid onto the inner part with theelastomer body and the plastic cage from above in the pre-assembly step.

Furthermore, it is advantageous if the elastomer body is connected tothe plastic cage in a vulcanisation step, wherein the plastic cage isinserted into a tool in a substantially form fit manner. This willprevent an undesirable deformation of the plastic cage during thevulcanisation process.

A bearing, more particularly a hydraulic axle support bearing, with aninner part, an outer part and an elastomer body which is arranged inbetween and is reinforced by a plastic cage, is also provided, whereinthe outer part has an upper edge and a lower edge and wherein theplastic cage projects over the upper edge and the lower edge of theouter part for the form fit axial securing of the outer part.Reinforcement by a cage made of plastic compared with a cage made ofsteel reduces the weight substantially, which in turns leads to areduction in CO₂ emissions in automotive engineering. Cost savings arealso possible as a result of this. Furthermore, using plastic for thecage offers the advantage of more options in terms of design.

According to a preferred embodiment, the plastic cage bears at leastpartially against an inner wall of the outer part, wherein the contactregion of the plastic cage on the inner wall of the outer partpreferably constitutes more than 20% of the curved surface area of theinner wall.

Preferably, the plastic cage has at least one sealing groove, moreparticularly a plurality of sealing grooves arranged on an outer side ofthe plastic cage, which groove is opposite the inner wall of the outerpart, wherein the at least one sealing groove is filled with anelastomer material. Preferably, the at least one sealing groove isfilled with the elastomer material of the elastomer body which can takeplace in one method step during production.

According to a further preferred embodiment, the plastic cage has atleast one web region, more particularly a plurality of web regions,which are lined at least in part. The lining gives the web regionsincreased stability. The web regions themselves serve to prevent theconstriction or even closure of bearing channels during the calibrationprocess.

Preferably, the radial stop is made of plastic. This will achieve alower overall weight. According to a further preferred embodiment, theradial stop is configured as an upper radial stop and arranged on anupper edge of the bearing.

Embodiments of the invention are described in greater detail below withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1E show different views of a bearing according to oneembodiment;

FIGS. 2A-2D show different views of a bearing according to a furtherembodiment;

FIGS. 3A-3F show different further views of a plastic cage according toone embodiment; and

FIGS. 4A-4F show different views of a plastic cage according to afurther embodiment.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1A to 1E show different views of a bearing 1 configured as ahydraulic axle support bearing according to one embodiment wherein FIG.1A represents an isometric view of the bearing 1, FIG. 1B a sectionalview through the bearing 1, FIG. 1C another sectional view through thebearing rotated 90° about the longitudinal axis L, FIG. 1D a top view ofthe bearing 1 and FIG. 1E a view from below. As can be seen particularlyfrom FIG. 1B, the bearing 1 has an inner part 2, a substantially hollowcylindrical outer part 3 made of aluminum and an elastomer body 21arranged between the inner part 2 and the outer part 3. The elastomerbody 21 forms balancing chambers 5 in fluid communication with eachother on radially opposing sides over a radial channel 14. Theright-hand balancing chamber 5 shown in FIG. 1B opens radially in theinside into a recessed filling channel 8 in the inner part 2.Furthermore, a radial stop 4 made of plastic is arranged on an upperedge of the bearing thus forming an upper radial stop. The upper radialstop is mounted on top of the inner part 2.

The elastomer body 21 is vulcanised onto the inner part 2. Moreover, afurther stop is provided as lower radial stop 9 on an axial end of theinner part 2, which supports an axial stop 10, which is mounted on afront side end or on the bottom side 6 of the inner part 2. The lowerradial stop 9 is also made of plastic. The axial stop is made ofaluminium.

The elastomer body 21 is reinforced by a plastic cage 11, which isvulcanised into the elastomer body 21. Sections of the plastic cage 11bear against an inner wall 7 of the outer part 3. A lower axial end 12and an upper axial end 12′ of the plastic cage 11 (see FIGS. 1B and 1C)are each formed radially outwards at 90° in order to project over alower edge 13 and an upper edge 13′ of the outer part 3 thereby axiallysecuring the outer part 3 in a form fit manner, and consequently theouter part 3 is held securely in an axial direction relative to theplastic cage 11 and thus the elastomer body 21.

Furthermore, the plastic cage 11 has web regions 15, which can be linedin order to demonstrate increased stability. The web regions 15 preventconstriction or closure of the radial channel 14 during the calibrationprocess.

FIGS. 2A to 2D show different views of a bearing 1 configured as ahydraulic axle support bearing according to a further embodiment,wherein FIG. 2A represents an isometric view of the bearing 1, FIG. 2B asectional view through bearing 1, FIG. 2C a top view of the bearing 1and FIG. 2D a view of the bearing 1 from below. The design of thebearing 1 shown here essentially corresponds to the design of thebearing 1 shown in FIGS. 1A to 1E and only differs in terms of thedesign of the axial stop 10 on the lower end of the bearing 1.

The bearing 1, which is shown in FIGS. 2A to 2D, as well as the bearing1, which is shown in FIGS. 1A to 1E, is produced as follows. In apreassembling step, the inner part 2, the elastomer body 21, the radialchannel 14 and the outer part 3 made of aluminium are assembled looselysuch that the plastic cage 11 is arranged directly on the inner wall 7of the outer part 3. The hollow cylindrical outer part 3 is slid on fromabove here. The plastic cage 11 protrudes radially over the outer part 3at both ends thereof, i.e. on the upper and lower edges 13, 13′. In thisuncalibrated state, the plastic cage 11 projects over the outer part 3only on the lower edge 13. In a subsequent calibration process, thealuminium outer part 3 is constricted, i.e. the diameter of the outerpart 3 is reduced by approx. 4 mm. However, not only the diameter of theouter part 3 is reduced in the process, but also the diameter of theplastic cage 11 in the same step. Clearance of 2 mm is assured with theloose pre-assembly. The resulting constriction of the plastic cage istherefore approx. 2 mm in diameter. Thus, both the outer part 3 and theplastic cage 11 are calibrated in a single method step. Aftercalibration, the plastic cage 11 then also projects over the outer part3 on the upper edge 13′ thereof and consequently creates the requiredaxial securing against sliding in an upwards direction.

FIGS. 3A to 3F show different further views of a plastic cage 11according to one embodiment, wherein FIG. 3A represents an isometricview of the plastic cage 11, FIG. 3B a sectional view through theplastic cage 11, FIG. 3C a further sectional view through the plasticcage 11 which, compared with the sectional view in FIG. 3B, is rotated90° about the longitudinal axis L of the plastic cage 11, FIG. 3D adetailed view of the upper edge 16 of the plastic cage 11, FIG. 3E aview of the plastic cage 11 from below and FIG. 3F a top view of theplastic cage 11. As can be seen here, the plastic cage 11 has two of theweb regions 15 described above. Furthermore, the plastic cage 11 has aplurality of sealing grooves 18 on its outer side 20 on an upper section17 and on a lower section 17′, which sealing grooves are opposite theinner wall 7 of the outer part 3 in the assembled state of the bearing 1(see, for example, FIG. 1B).

The sealing grooves 18 are filled with elastomer material during theprocess of spraying the elastomer body 21.

Moreover, it can be seen in the detailed view of the upper edge 16 ofthe plastic cage 11 shown in FIG. 3D (characterised by A in FIG. 3B),that the upper edge 16 curves outwards and is thus rounded. In contrastto this, the lower protruding edge 16′ of the plastic cage 11 is notcurved.

FIGS. 4A to 4F show different views of a plastic cage 11 according to afurther embodiment, wherein FIG. 4A represents an isomeric view of theplastic cage 11, FIG. 4B a sectional view through the plastic cage 11,FIG. 4C a further sectional view through the plastic cage 11, whichcompared with the sectional view in FIG. 4B, is rotated 90° about thelongitudinal axis L of the plastic cage 11, FIG. 4D a detailed view ofthe upper edge 16 of the plastic cage 11 (characterised by A in FIG.4B), FIG. 4E a view of the plastic cage 11 from below and FIG. 4F a topview of the plastic cage 11. The embodiment of the plastic cage 11 shownhere differs from the embodiment shown in FIGS. 3A to 3F, firstly inthat the upper edge 16 of the plastic cage 11, which is shown in detailin FIG. 4D, is rounded, but not does not curve outwards, and secondly inthat the lower edge 16′ is provided with two conical support contours19, 19′ that point downwards and are angled slightly outwards.

Thus, while there have been shown, described, and pointed outfundamental novel features of the invention as applied to a preferredembodiment thereof, it will be understood that various omissions,substitutions, and changes in the form and details of the devicesillustrated, and in their operation, may be made by those skilled in theart without departing from the spirit and scope of the invention. Forexample, it is expressly intended that all combinations of thoseelements and/or steps that perform substantially the same function, insubstantially the same way, to achieve the same results be within thescope of the invention. Substitutions of elements from one describedembodiment to another are also fully intended and contemplated. It isalso to be understood that the drawings are not necessarily drawn toscale, but that they are merely conceptual in nature. It is theintention, therefore, to be limited only as indicated by the scope ofthe claims appended hereto.

Every issued patent, pending patent application, publication, journalarticle, book or any other reference cited herein is each incorporatedby reference in their entirety.

1. A method for producing a bearing, comprising the steps of:preassembling an inner part in an outer part with an elastomer bodydisposed therebetween, the elastomer body being reinforced by a plasticcage, the plastic cage at least partially bearing against an inner wallof the outer part; wherein the plastic cage is configured to protruderadially over an upper edge and to protrude over and project beyond alower edge of the outer part; wherein, in an uncalibrated state, theplastic cage projects over the outer part only on the lower edge; andsimultaneously calibrating the outer part and the plastic cage byconstricting the outer part and the plastic cage from a respective firstdiameter to a respective second diameter, wherein, after theconstriction, the plastic cage projects over the upper edge of the outerpart for form-fitting axial securing of the outer part.
 2. The method inaccordance with claim 1, wherein there is clearance during thepreassembling step.
 3. The method in accordance with claim 1, whereinthe constricting of the outer part from the first diameter to the seconddiameter comprises constricting by at least 3 mm.
 4. The method inaccordance with claim 3, wherein the constricting of the outer part fromthe first diameter to the second diameter comprises constricting byapproximately 4 mm.
 5. The method in accordance with claim 1, wherein inthe preassembling step, the outer part is slid onto the inner part withthe elastomer body and the plastic cage from above.
 6. The method inaccordance with claim 1, wherein the elastomer body is connected to theplastic cage in a vulcanization step, and wherein the plastic cage isplaced into a tool substantially in a form fit manner.
 7. The method inaccordance with claim 1, wherein the bearing is a hydraulic axle supportbearing.
 8. The method in accordance with claim 1, wherein at least someareas of the plastic cage directly bear against an inner wall of theouter part.
 9. The method in accordance with claim 1, wherein thecontact region of the plastic cage against the inner wall of the outerpart is more than 20% of the curved surface area of the inner wall. 10.The method in accordance with claim 1, wherein: the plastic cage has atleast one sealing groove arranged on an outer side of the plastic cage,the outer side of the plastic cage being opposite the inner wall of theouter part; and the at least one sealing groove is filled with anelastomer material.
 11. The method in accordance with claim 10, whereinthe at least one sealing groove comprises a plurality of sealinggrooves.
 12. The method in accordance with claim 1, wherein the plasticcage has at least one web region.
 13. The method in accordance withclaim 12, wherein the at least one web region comprises a plurality ofweb regions.
 14. The method in accordance with claim 1, furthercomprising a radial stop made of plastic.
 15. The method in accordancewith claim 14, wherein the radial stop is configured as an upper radialstop and arranged on an upper edge of the bearing.
 16. The method inaccordance with claim 1, wherein the bearing is a hydraulic axle supportbearing.
 17. The method in accordance with claim 1, wherein during thepreassembling step, the inner part, the elastomer body and the outerpart are assembled loosely.
 18. The method in accordance with claim 17,wherein with the loose preassembly, clearance of approximately 2 mm isassured and resulting constriction of the plastic cage is approximately2 mm in diameter.